The removal of carbon dioxide, other acid gases, and contaminants from flue gas, syngas, and other gas streams is often accomplished by desublimation into cryogenic liquids, resulting in a cryogenic slurry. The ability to separate these and other cryogenic solids from a cryogenic liquid is of critical importance to greenhouse gas mitigation efforts. However, most separation technologies are ineffective, inefficient, expensive, or all three.
Cross-flow filtration, sometimes referred to as tangential filtration, is a common method for removing solids in reverse osmosis, nanofiltration, ultrafiltration, and microfiltration. Most modern applications are in biotechnology, wastewater treatment, and mineral processing. Common filter media include various textiles, cellulose, room-temperature and elevated-temperature ceramics, and sand. The ceramics used are not suitable for cryogenics. Filter media still tends to collect solids over time unless a filter media is selected on which the solids do not easily adsorb. Solids to be filtered are sent to laboratories where large numbers of filter media are tested until the ideal filter media is found. While there are filter media intended for dead-end style filters, no filter media available commercially is intended for or tested for cross-flow filtration of cryogenic temperature solids, such as acid gas solids.
A method and apparatus capable of overcoming these and other obstacles is needed for cryogenic solid-liquid separations.
U.S. Pat. No. 5,749,232 to Sauer teaches an apparatus and method for producing and injecting sterile cryogenic liquids. The cryogenic liquids are filtered through a dead-end style filter that filters and retains microbes from the liquid using sintered ceramic material filters. The present disclosure differs from this disclosure in that the filter media retains foulants rather than removing them, and therefore has to be shut down to clean or replace the filter media. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 2,364,366 to Jahreis teaches fractional removal of liquids from liquid-solid suspensions. Most prior art in this disclosure relies on the teachings of this publication for the basic design or method of their disclosures. This publication discusses the idea of passing a slurry through a channel tangential to the surface of a filter cloth to provide fractional removal of liquids from the slurry. The present disclosure differs from this disclosure in that this disclosure makes no accommodations for removing liquids from a cryogenic slurry. This disclosure utilizes wood and metal plates, which are not suitable for cryogenic slurries. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 2,417,958 to Teale teaches an apparatus for reducing the fluid content of a fluid-solid intermixture. This disclosure teaches the same concepts as the first prior art, above, with modified, horizontal plates. The present disclosure differs from this disclosure in that this disclosure makes no accommodations for removing liquids from a cryogenic slurry. This disclosure provides only for “non-rigid” or “pliable” materials, and does not anticipate the need for materials that could handle extremely low temperatures. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 3,502,211 to Von Polnitz et al. teaches a process and apparatus for recovering solids in enriched and purified form. This disclosure teaches the same concepts as the first prior art, above, with modified plates and a reversible flow for filter media cleaning. The present disclosure differs from this disclosure in that this disclosure makes no accommodations for removing liquids from a cryogenic slurry, making no disclosure as to what materials with which to construct the apparatus. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 5,240,605 to Winzeler teaches a spiral filter for removal of aerosols, gaseous and liquid suspensions, and colloidal or true solutions. This disclosure teaches the same concepts as the first prior art, above, with round plates and the ability to filter gas phase suspensions. The present disclosure differs from this disclosure in that this disclosure teaches methods of handling ambient or similar temperature gases, and not cryogenic liquids. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 6,312,591 to Vassarotti teaches a spiral filter for removal of aerosols, gaseous and liquid suspensions, and colloidal or true solutions. This disclosure teaches the same concepts as the first prior art, above, with round plates and the ability to filter gas phase suspensions. The present disclosure differs from this disclosure in that this disclosure teaches methods of handling ambient or similar temperature gases, and not cryogenic liquids. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 3,398,834 to Nuttall et al. teaches an apparatus for reverse osmosis water purification. The present disclosure differs from this disclosure in that this disclosure utilizes reverse osmosis. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.